[[<tvar|brion>User:Brion VIBBER</>|Brion]] [<tvar|wikitech-l>https://lists.wikimedia.org/pipermail/wikitech-l/2006-November/027752.html</> announced] a successful migration test in November 2006. Data collection took two hours and automatic merging took five hours. 4,457,075 primary accounts were confirmed, with 578,128 secondary accounts merged automatically based on matching email addresses or by cannibalizing unused accounts. 134,242 secondary accounts will need to be merged with user interaction (71,741 unique user names have accounts left unmerged).

Unified login was implemented for administrators only in March 2008, and [<tvar|sr-sul>//meta.wikimedia.org/wiki/Steward_requests/SUL_requests?redirect=no</> Steward requests/SUL requests] (now a redirect to [[<tvar|sr-uc>Steward requests/Username changes</>|SRUC]]) was created to resolve conflicts in unified logins. Unified login was enabled for all users on May 27, 2008 on an opt-in basis. On August 22, 2008, CentralAuth was set to make a global account for all users registered after this date. The change removed the need for manual merging of accounts.

On 30 April 2013, the Wikimedia Foundation announced that the unified login system would be changing so that there would be only unique global accounts with the same username across all Wikimedia projects; there would be no two users sharing the same username on different wikis. With SUL finalization, all non-global accounts will be converted to global accounts where possible and if there is clash in the username, they will be renamed to have a "<tvar|code>~</>" and the wiki name will be appended to the username. For example, an account with the username "Example" on the Dutch Wiktionary, which will be renamed, would become "Example~nlwiktionary". Initially, it was announced to take place in May 2013. However, this was delayed to August 2013, and in August 2013, this expectation was removed.

As part of this process, GlobalRenameUser function was introduced in July 2014 and the local rename user tool was removed from bureaucrats' toolset in September 2014.

The mass renaming process of users with conflicts in username started on 15 April 2015 and was finished by 22 April 2015. Since 15 July 2015, only users with unified global accounts are allowed to login on Wikimedia projects.

This document so predominantly so represents a past time. We should be focusing this document on what SUL is today. If we need to point historical aspects, then they can be through see also links to the old version(s). 22:32, 31 January 2019 (UTC)
—The preceding unsigned comment was added by Billinghurst (talk)